POJ 3635 Full Tank?
题目链接: http://poj.org/problem?id=3635
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把操作的费用作为边的长度 把实际的边的长度转化为点之间的关系 是一道很有意思的题目
已经得到终点最小距离后立即退出会快点
另外注意内存计算要细心(或者直接粗略计算后多开10%)
1 #include <cstdio> 2 #include <cstring> 3 #include <cmath> 4 #include <algorithm> 5 #include <queue> 6 using namespace std; 7 const int N = 11e4, E = 22e5, mod = 101, inf = 1e9 + 10; 8 struct node 9 { 10 int num, d; 11 node(){} 12 node(int x, int y) 13 { 14 num = x; 15 d = y; 16 } 17 }; 18 int oil[1010], dist[N], used[N]; 19 int firste[N], nexte[E], v[E], w[E]; 20 int n, m, e = 1, t; 21 bool operator < (const node &aa, const node &bb) 22 { 23 return aa.d > bb.d; 24 } 25 priority_queue<node>q; 26 void build(int x, int y, int z) 27 { 28 nexte[++e] = firste[x]; 29 firste[x] = e; 30 v[e] = y; 31 w[e] = z; 32 } 33 void dijkstra(int c, int s, int f) 34 { 35 for(int i = 0; i < n; ++i) 36 for(int j = 0; j <= c; ++j) 37 dist[i * mod + j] = inf; 38 dist[s * mod] = 0; 39 q.push(node(s * mod, 0)); 40 int u, di; 41 while(!q.empty()) 42 { 43 u = q.top().num; 44 di = q.top().d; 45 q.pop(); 46 if(used[u] == t || u % mod > c) 47 continue; 48 if(u == f * mod) 49 break; 50 used[u] = t; 51 for(int p = firste[u]; p; p = nexte[p]) 52 if(dist[v[p]] > di + w[p]) 53 { 54 dist[v[p]] = di + w[p]; 55 q.push(node(v[p], dist[v[p]])); 56 } 57 } 58 while(!q.empty()) 59 q.pop(); 60 if(dist[f * mod] < inf) 61 printf("%d\n", dist[f * mod]); 62 else 63 puts("impossible"); 64 } 65 int main() 66 { 67 scanf("%d%d", &n, &m); 68 for(int i = 0; i < n; ++i) 69 { 70 scanf("%d", &oil[i]); 71 for(int j = 0; j < 100; ++j) 72 build(i * mod + j, i * mod + j + 1, oil[i]); 73 } 74 int x, y, z; 75 while(m--) 76 { 77 scanf("%d%d%d", &x, &y, &z); 78 for(int i = z; i <= 100; ++i) 79 { 80 build(x * mod + i, y * mod + i - z, 0); 81 build(y * mod + i, x * mod + i - z, 0); 82 } 83 } 84 memset(used, -1, sizeof used); 85 scanf("%d", &t); 86 int c, s, f; 87 while(t--) 88 { 89 scanf("%d%d%d", &c, &s, &f); 90 dijkstra(c, s, f); 91 } 92 return 0; 93 }